1. Field of the Invention
The present invention relates generally to camera capture and, more specifically, to an approach for camera control.
2. Description of the Related Art
Mobile devices having a digital camera, a display, an adequate computational power, and a touch interface are becoming increasingly commonplace, and increasingly powerful. More photographs are captured by mobile devices now than ever, and many of them are edited directly on device and shared directly from that device, without ever even being uploaded to PCs. This phenomenon is well-reflected in the recent focus on camera control and image processing on mobile platforms and also in the popularity of photography apps on smart phones.
A typical digital camera, whether a feature-rich digital single lens reflex (DSLR) or a point-and-shoot device, relies on a set of knobs and buttons to control capture parameters. In a standalone photographic pipeline, the user selects a predefined shooting mode that specifies the camera metering strategy (e.g., daylight, night-mode, spot-mode, panorama, macro-photography, etc.), captures an image while potentially adjusting capture parameters with sliders or dials. Then, as an optional post-processing step, the user performs edits to correct for undesired metering settings (e.g., picture or specific regions are over/under-exposed, add synthetic blur to background to emphasize foreground, etc.). This approach, resulting from almost a century of photography evolution, is effective but poses some difficulties for inexperienced camera users. Point-and-shoot cameras tend to produce sub-optimal images due to primitive metering strategies that do not reflect user's intentions, while DSLR are difficult to operate without in-depth knowledge of photography. On top of that, a direct port of knob and buttons interface does not fully utilize the potential of the touch-based interface available on many mobile devices.
Early photographers could not directly see the results as they were taking photos, but had to imagine the results as a function of various imaging parameters such as exposure, focus, even choice of film and paper that were used. Digital cameras with real-time digital displays that show a preview image have made photography much easier in this respect. Framing the image and choosing the timing of capture is made easier and more fun as the camera gives a preview of what the captured image will look like. However, when using many computational photography techniques the user still needs to imagine the result of, for example, combining an exposure burst into a high dynamic range (HDR) image and tone-mapping the HDR image back to low dynamic range (LDR) for display, rather than seeing an approximation of the end result in a digital viewfinder. Similar limitations apply also to traditional digital photography. Many photographers edit their photographs after capture, using tools such as Photoshop or Lightroom. Unfortunately, users must capture the shot in the field before knowing the effect such later edits might have on the result. The capture process thus remains separated from the image editing process, potentially leading to inadequate data acquisition (e.g., wrong composition or insufficient signal-to-noise ratio (SNR)) or excessive data acquisition (e.g., longer capture time, exacerbated handshake or motion blur, and increased cost of storage or transmission.)
Accordingly, typical digital cameras provide a digital viewfinder with a somewhat faithful depiction of the final image. If, however, the image is created from a burst of differently captured images, or non-linear interactive edits have a significant contribution to the final outcome, the photographer cannot directly see the results, but needs to imagine the post-processing effects.
Accordingly, what is needed is a camera that enables capturing a scene that more accurately represents the user's intent at the moment of actuating the shutter.